A SEA OF How we're rethinking our relationship with the ocean - Fossil Rivers of the Green Sahara - Eos.org
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VOL. 103 | NO. 2 Fossil Rivers of the
FEBRUARY 2022
Green Sahara
A Chip off the Old Moon
How Armero
Changed Volcanology
A SEA OF
How we’re
rethinking our
relationship
with the ocean
FROM THE EDITOR
Editor in Chief
Heather Goss, Eos_EIC@agu.org
Science Off the Seashore AGU Staff
Editorial
Managing Editor
I
Caryl-Sue Micalizio
n January 2021, the United Nations launched the Decade Senior Science Editor Timothy Oleson
Associate Editor Alexandra Scammell
of Ocean Science for Sustainable Development. The initia-
News and Features Writer Kimberly M. S. Cartier
tive encourages partner nations to fund scientific research News and Features Writer Jenessa Duncombe
that “achieves the ocean we want by 2030.” Calls have gone
out, proposals are being pitched, and here at Eos we very much Production & Design
Assistant Director, Operations Faith A. Ishii
look forward to seeing this global coalition work toward the
Production and Analytics Specialist Anaise Aristide
seven goals the United Nations has outlined. (Read more at Assistant Director, Design & Branding Beth Bagley
oceandecade.org.) Senior Graphic Designer Valerie Friedman
Inspired by this movement, Eos dedicates this issue—and Senior Graphic Designer J. Henry Pereira
Multimedia Graphic Designer Mary Heinrichs
one issue each year through 2030—to the study of the ocean
and our relationship with it. We start our decade-long watch Marketing
on page 22 with a ship that’s tied to a 402-year-old event. The Assistant Director, Marketing & Advertising Liz Zipse
Mayflower Autonomous Ship, or MAS, is the futuristic namesake
of the original Mayflower, which set sail from Plymouth, England, in 1620. MAS will retrace that
Advertising
Display Advertising Steve West
voyage later this year, guided by an artificial intelligence (AI) captain, as a technology show- steve@mediawestinc.com
case of how we might study the expansive ocean without having to send humans sailing over Recruitment Advertising recruitmentsales@wiley.com
every inch of it.
Next, we report on a bright idea that can’t seem to get off the ground, or perhaps I should Science Advisers
Geodesy Surendra Adhikari
say, up from the deep sea. Ocean thermal energy conversion is a fairly simple concept that
Hydrology José Luis Arumi
could help island nations find independence from fossil fuels, but it’s suffering from the “inno- Natural Hazards Paula R. Buchanan
vation valley of death.” Read more about the potential of this ocean-based power source (p. 28) GeoHealth Helena Chapman
and, if you have a few billion lying around, perhaps give someone on the island of Kumejima Atmospheric and Space Electricity Kenneth L. Cummins
Space Physics and Aeronomy Jingnan Guo
a call? History of Geophysics Kristine C. Harper
We end our feature reporting with an ominously ticking clock. The deep-sea mining indus- Planetary Sciences Sarah M. Hörst
try is impatiently waiting for international regulators to take the leash off so they can begin Volcanology, Geochemistry, and Petrology Emily R. Johnson
Cryosphere Michalea King
collection of the rare earth elements waiting on the floor of the Clarion-Clipperton Zone in Societal Impacts and Policy Sciences Christine Kirchhoff
the Pacific. We report on page 36 on the stakes that are all going to become clear in less than Seismology Ved Lekic
2 years—for the ocean ecosystems, for the investors in deep-sea mining, and for the renew- Mineral and Rock Physics Jie “Jackie” Li
Tectonophysics Jian Lin
able energy tech that currently depends on these resources. Near-Surface Geophysics Juan Lorenzo
I also urge you to take a look at Jeremy Bassis’s excellent Opinion on page 19, “Quit Worry- Earth and Space Science Informatics Kirk Martinez
ing About Uncertainty in Sea Level Projects.” Bassis offers an eloquent explainer on how cli- Ocean Sciences Jerry L. Miller
Atmospheric Sciences Vaishali Naik
mate scientists can refocus the way they communicate their research to be of better use to
Study of the Earth’s Deep Interior Rita Parai
policymakers. Education Eric M. Riggs
Thanks once again to our friend Russ Colson, who brings us a sea-themed crossword puzzle Global Environmental Change Hansi Singh
Geomagnetism, Paleomagnetism,
to close the issue. See you next month!
and Electromagnetism Nick Swanson-Hysell
Paleoceanography and Paleoclimatology Kaustubh Thirumalai
Nonlinear Geophysics Adrian Tuck
Biogeosciences Merritt Turetsky
Hydrology Adam S. Ward
Diversity and Inclusion Lisa D. White
Earth and Planetary Surface Processes Andrew C. Wilcox
Heather Goss, Editor in Chief
©2022. AGU. All Rights Reserved. Material in this issue may be photocopied by
individual scientists for research or classroom use. Permission is also granted to use
short quotes, figures, and tables for publication in scientific books and journals. For
permission for any other uses, contact the AGU Publications Office.
Eos: Science News by AGU (ISSN 0096-3941) is published monthly except December
by the American Geophysical Union, 2000 Florida Ave., NW, Washington, DC 20009,
USA. Periodical Class postage paid at Washington, D.C., and at additional mailing
offices. POSTMASTER: Send address changes to Eos: Science News by AGU, Member
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Submit your article proposal or suggest a news story to Eos at bit.ly/Eos-proposal.
Views expressed in this publication do not necessarily reflect official positions
of AGU unless expressly stated.
Randy Fiser, Executive Director/CEO
SCIENCE NEWS BY AGU // Eos.org 1
CONTENT
28
22 36
Features
22 A New Mayflower, Named 28 The Century-Old Renewable
for the Past, Autonomously You’ve Never Heard Of
Navigates the Future By Mark Betancourt
By Alka Tripathy-Lang Are you a climate-conscious billionaire in need of a
perfect project?
A high-tech ship will chart a new path by retracing
an old one.
36 The 2-Year Countdown
to Deep-Sea Mining
By Jenessa Duncombe
On the Cover
A view of the seafloor and an island in the Maldives. Murky waters surround an industry that’s positioned
Credit: Ishan @seefromthesky/Unsplash on the starting block.
2 Eos // FEBRUARY 2022
CONTENT
4 19
8 44
Columns
From the Editor Opinion
1 Science Off the Seashore 19 Quit Worrying About Uncertainty in Sea Level
Projections
News
4 Ancient Fish Thrived During a Period of Rapid
Research Spotlight
Global Warming 43 Seismology: A Promising Tool for Monitoring
5 Hundreds of Volcanic Explosions Detected Permafrost
Underwater at Kı̄lauea 44 Shedding Light on Microbial Communities in Deep
6 Scientists Plan a Home Away from Home Aquifers | Unifying Models of Chorus Wave Frequency
for Mars Samples Chirping
8 Bright Lights, Big Cities Attract Migratory Birds 45 Measuring Sea Level Rise Along Coasts | Subduction
9 Peruvian Farmers Threatened by Water Stress Initiation May Depend on a Tectonic Plate’s History
10 Hostile Workplaces Drive Minorities from Geoscience 46 River Ice Can Shape Watershed Ecology
11 A Hotter Earth Means Stronger Tornadoes
12 Earthquakes Ripple Through 3D-Printed Models Editors’ Highlights
of Los Angeles
47 Good, Soon, and Cheap: Earthquake Early Warning
13 Asteroid May Be a Chip off the Old Moon
by Smartphone | Sea-Level Science Coordination:
14 A New Technique Could Identify Algae from Space A U.S. and Global Concern
15 The “Green Sahara” Left Behind Fossil Rivers
16 How the Armero Tragedy Changed Volcanology
in Colombia
Positions Available
18 Roman-Era Millstone and Mixer Makers Knew 48 Current job openings in the Earth and space sciences
Their Rocks
Crossword
49 Treasures of the Sea
AmericanGeophysicalUnion @AGU_Eos company/american-geophysical-union AGUvideos americangeophysicalunion americangeophysicalunion
SCIENCE NEWS BY AGU // Eos.org 3
NEWS
Ancient Fish Thrived During a Period
of Rapid Global Warming
heat up may very well be accurate, but evi-
dence suggests that will flip in the long term,
he said.
Still, Sibert urged caution when compar-
ing fish outcomes during the PETM and what
might happen this century—and beyond.
“The rate of warming…can have dramatic and
differential impacts on marine ecosystems,”
she noted.
Modern seas face a myriad of challenges
beyond rising temperatures, including over-
fishing and pollution. Therefore, we may need
to look to more recent history for an analogue
for the modern ocean, said Chris Free, an
ecologist at the University of California, Santa
Barbara who was not involved in the research.
A
bout 55 million years ago, Earth’s cli- Pacific, eastern equatorial Pacific, and Atlan- “To prepare coastal communities, liveli-
mate underwent a rapid and intense tic oceans. The researchers filtered micro- hoods, and food systems for climate change,
period of warming, both on land and scopic fish scales and teeth from varying we need to have realistic expectations for
at sea. Temperatures soared by more than 5°C, depths of the sediment core, counting and likely impacts. Recent history may provide a
and even Arctic seas turned tropical. Recon- sorting them for a window into past ocean life more instructive road map for the challenges
structing this warm era, the Paleocene-Eocene during the PETM. ahead,” he said.
Thermal Maximum (PETM), provides a glimpse “This is the first time we have an idea of
into Earth’s possible future. “One of the best what mid to upper trophic level groups were
tools we have to understand how the [ocean] doing during this warming event,” said team
system responds is to look at past instances of member Richard Norris, a paleobiologist at
global change,” said Elizabeth Sibert, a pale- the Scripps Institution of Oceanography.
“There’s increasing
oceanographer and paleoecologist at the Yale “Previously, almost all studies of the PETM evidence that in past warm
Institute for Biospheric Studies. have been based upon unicellular plankton or
By examining fossil evidence from the microzooplankton.”
periods in Earth’s history,
PETM preserved in marine sediment cores, The results paint a consistent picture of the biological production
Sibert and her colleagues sought to under- past across all three samples: Fish became
stand how fish might respond to warming more abundant as temperatures climbed, actually went up in the
oceans. Contrary to the predictions of many then gradually decreased again as the warm- ocean.”
models, they found that fish actually grew ing waned. Plus, the various fish types didn’t
more abundant as temperatures soared. change much during this temperature flux.
Sibert and her team presented their research “It’s really surprising,” said Norris. “You’d
at AGU’s Fall Meeting 2021 (bit .ly/ fish think that as things warm up you might get a
-resilience). really different community of fishes.” Sibert and her fellow researchers plan to
expand the study with additional sediment
Oceans of the Past An Imperfect Proxy records from environments beyond tropical
When marine fish die, either they sink to These results are notably different from what regions to better understand whether their
the depths of the sea and decompose, or current fisheries models predict as Earth results represent a global phenomenon
they are eaten by other marine life and faces another period of rapid warming. These during the PETM. They will also continue to
expelled through fecal matter. In either case, alternate predictions could arise from a dif- refine their research by further accounting for
corrosion-resistant teeth and scales settle ference in timescales, the researchers noted. variation in sedimentation rates and density
onto the seafloor and accumulate in sedi- For example, forecasting models often look to increase their confidence in the results. But
ments. Layers of these sediments build up at decades to a century, whereas sediment their preliminary findings are hopeful, at
over millions of years, preserving records of records offer glimpses of change over hun- least in the long term, Sibert said: “Fish may
fish abundance and diversity over time for dreds to thousands of years. be more resilient to global change than pre-
scientists to decipher. Despite this mismatch, “there’s increasing viously thought.”
Sibert and her team examined sediment evidence that in past warm periods in Earth’s
records in three different cores collected by history, biological production actually went
the Ocean Drilling Program. The drill sites up in the ocean,” said Norris. Models that By Elyse DeFranco (@elyse_defranco), Science
spanned tropical reaches of the north central predict a dip in fish populations as the seas Writer
4 Eos // FEBRUARY 2022
NEWS
Hundreds of Volcanic Explosions Detected Underwater
at Kīlauea
O
n 16 July 2018, a lava bomb from the
Kılauea volcano tore through the roof
of a tour boat just off the Big Island of
Hawaii. Sightseers on board described blobs
of molten rock smashing into the boat out of
nowhere—injuring 23 passengers and break-
ing a woman’s leg.
Now scientists have collaborated with
those on the boat to pinpoint the acoustic
fingerprint of lava explosions. The finding
helped researchers identify hundreds of
blasts in the area that year.
Shortly after Kılauea entered a new erup-
tive phase in May 2018, geophysicist Yang
Shen and his collaborators installed ocean
bottom instruments at 11 locations near the
southeastern flank of the volcano. The sen-
sors, placed between 700 and 5,000 meters
deep, recorded underwater signals from
earthquakes and the outpouring of lava into
the sea.
Lava-water explosions in the ocean are
steam-driven blasts that in some instances
shoot blobs of lava hundreds of meters into
the air. These outbursts, called lava bombs,
have unique underwater sound signatures, Lava from Kīlauea formed a small new island on 13 July 2018 (left). A molten lava bomb burst through the roof of
too. “It’s very different from earthquakes or a Lava Ocean Tours boat (right) 3 days later while tourists watched the lava. Credit: Hawaii Department of Land
submarine landslides,” said Shen, a professor and Natural Resources (left), HVO (right)
Opposite: Sebastian Pena Lambarri/Unsplash
The lava bomb that hit the tour boat showed up in spectrograms of ocean noise
A map of the southeastern flank of Kīlauea volcano on Hawaii’s Big Island. Red on 16 July 2018. The spectrogram describes the changes in frequency in hertz over
lines trace the flow of the lava as it met the sea, the gray star shows the location 50 seconds. Arrows denote the explosion at four different hydrophones underwa-
of the tour boat that was struck, and the yellow triangles are the underwater ter near the volcano. The sound waves arrived at slightly different times depend-
hydrophones placed by the researchers. Credit: Puja Banerjee and Yang Shen ing on the sensors’ location. Credit: Puja Banerjee and Yang Shen
SCIENCE NEWS BY AGU // Eos.org 5
NEWS
of oceanography at the University of Rhode
Island (URI).
Scientists Plan a Home Away
Using time and location data from photo-
graphs taken on the tour boat, URI Ph.D.
from Home for Mars Samples
student Puja Banerjee determined the acous-
P
tic fingerprint of the 16 July lava bomb using erseverance has barely started its rock (NASA hasn’t given formal approval for the
four underwater microphones, or hydro- hounding on Mars, but scientists are return mission, although it is expected to do
phones. She then combed through the already planning how to handle the so, with launch targeted before 2030.)
acoustic data from that summer and found rover’s samples when they’re dispatched to NASA and ESA still have to work out the
that from early July to early August, when Earth. They’re pondering how to keep the details on a receiving and curation laboratory
the eruption ended, there were at least 644 samples safe from Earth and Earth safe from for the samples, including its size, the scien-
lava explosions in the area. She presented the samples while making them accessible to tific gear it will contain, its location, and even
the research, which has not yet been peer researchers for decades to come. whether they might want more than one
reviewed, at AGU’s Fall Meeting 2021 (bit.ly/ The potential for life on Mars “is a twofold facility. But the advisory committee, MSR Sci-
lava-bombs). thing,” said Carl Agee, director of the Insti- ence Planning Group Phase 2 (MSPG2, some
The work “has important implications for tute of Meteoritics at the University of New of whose findings were presented at AGU’s
mitigating future volcanic hazards,” said Mexico and a member of an advisory commit- Fall Meeting 2021), and experts within both
Robert Dziak, an acoustics scientist at NOAA’s tee that reviewed requirements for a possible agencies have outlined the basic challenges
Pacific Marine Environmental Laboratory Mars sample facility. “It’s the major science and requirements (bit.ly/mars-sample).
who wasn’t involved in the research. The driver for a sample return mission, the major
study reveals a hot spot along the coastline science motivator. But it’s also a major hurdle Protecting Earth from Mars
where the highest number of hydrovolcanic that has to be overcome. You have to protect The key requirements are to evaluate whether
explosions occurred. Earth from potential microscopic organisms, the samples contain any living organisms
Particles ejected from volcanoes can range but you also have to prevent contamination and, if so, to keep them locked safely away,
in size from dust and ash (millimeters) to in the samples so you don’t have any confu- preventing any possible contagion.
lapilli (“little stones” of several centimeters) sion if they have evidence of life.” “The chances they will contain extant life
to bombs (6 centimeters to several meters). Perseverance, which has trundled through are extremely low,” said Andrea Harrington,
Lava explosions don’t always shoot lava Jezero crater since February, is the first half Mars sample curator at Johnson Space Center.
into the air, but when they do, the result can of a possible two-step Mars Sample Return “If we find something, it’s more likely to
be deadly. In 1992, one person was killed and (MSR) mission. It will collect almost 40 core be extinct. But we’re taking a very careful
three others were seriously injured when lava samples, each about the size of a stick of approach. We’ll protect Earth from the sam-
bombs exploded from Mount Marapi in Indo- chalk, in titanium tubes, which will be sealed ples.”
nesia. In Hawaii in 2018, a bowling ball–sized tightly. The rover will deposit the samples for Initially, the samples will be stored and
lava bomb hit a man on the leg outside his collection by a second rover, which is under handled in a biosafety level 4 facility, which
home. development by the European Space Agency provides the highest level of protection against
Eruptions on land can launch lava bombs, (ESA). The retrieval rover will load the sam- releasing dangerous agents into the environ-
too. The explosions are caused by dissolved ples inside a small rocket, which will ferry ment. The air pressure will be lower inside the
gas or vapor in lava that comes out of solution them to a Mars orbiter for the trip to Earth. facility, ensuring that nothing accidentally
and forms bubbles that then explode.
More than 80% of volcanic eruptions occur
in the ocean, said Shen. “We might be able to
use those natural acoustic signals to study
how acoustic waves propagate in the ocean.”
Scientists could use the relationship
between acoustic wave speed and seawater
temperature to study how climate change is
affecting ocean waters, said Yang. The short,
clear sound bursts from lava-water explo-
sions may be easier to decipher than the more
complex acoustic signals from underwater
earthquakes.
Previous research has suggested that sound
from lava-water explosions travels far:
Hydrophones placed more than 5,000 kilo-
meters from Kılauea recorded explosions,
according to a 2001 study.
By Jenessa Duncombe (@jrdscience), Staff Perseverance is shown here next to Rochette, the rock from which it extracted the first two samples for possible
Writer return to Earth. Credit: NASA/JPL-Caltech/MSSS
6 Eos // FEBRUARY 2022
NEWS
what to ask for,” said Agee, who worked more
than 2 decades ago at NASA’s lunar samples
facility, where he studied concepts for a Mars
sample lab to support an earlier mission con-
cept. “It’s like a library book. You want to
know the title, the author—a few basic
things. The point is, we want to have every-
thing accessible to the broader research com-
munity as soon as possible.”
Once the samples are ready, the facility will
dole out tiny amounts of them—milligrams
or even micrograms at a time. With the
amount of material expected to be returned
from Perseverance’s excursion, that’s enough
for researchers to conduct thousands of stud-
ies, Tait said. “There will be more than
enough material for my lifetime and the life-
times of many future observers.”
Planning for the Future
Keeping the samples in good shape for those
future scientists is another focus of a storage
facility. Samples gathered by Apollo astro-
This artist’s conception shows an ascent vehicle carrying samples collected by Perseverance as it heads toward nauts have been stored at Johnson Space Cen-
a rendezvous with the Earth return craft in orbit around Mars. Credit: NASA/JPL-Caltech ter for almost half a century, with some
opened and studied for the first time in just
the past few years. A Mars laboratory must be
prepared to keep its samples safe and ready
flows out. Samples will be stored and evaluated Initial analysis might include extracting for new scientific investigations for a similar
in sterilized cabinets made from special mate- some of the Martian atmosphere from the span, with some lying untouched for decades.
rials and filled with nitrogen or other gases, core tubes, conducting X-ray tomography or “We have to be ready for however long
and planners are considering fully robotic sys- computed tomography (CT) scans to get an people want to continue doing science,” said
tems for handling the samples. idea of what’s inside the tubes, taking micro- Harrington. “We have to be able to get a lot of
Once they are proven to be free of Martian science out of the samples beyond the first
bugs, the samples will be moved to less couple of years. That’s the plan.”
restrictive quarters, where the emphasis will Planners are looking at the experience of
be on protecting them from Earthly contam- “You have to protect Earth the Apollo curation team to determine what
ination. “We want to protect them from has worked well and what hasn’t.
humidity, dirt, microbes, fungus, people with
from potential microscopic “In the Apollo curation facility, a lot of the
grubby fingers—you name it,” said Agee. organisms, but you also best practices have been developed since the
“They’ll be kept extremely clean and pris- 1970s, and a lot of them will be adapted for
tine.” have to prevent the Mars samples,” said Agee. “A lot of the
contamination in the mistakes have already happened, so we don’t
On to the Science have to go through that again.”
Most of the detailed scientific work will be samples so you don’t have NASA has initiated a study to determine a
performed by individual scientists at their any confusion if they have specific plan for the Mars sample facility,
own laboratories, so the initial evaluations at which will take several years to build and test.
the sample return facility will be designed to evidence of life.” The agency is considering everything from
prevent altering or contaminating the sam- renting a relatively small facility to building
ples in any way. a larger new one, with a ready-to-receive date
“The first step will be a basic characteriza- of 2031 or 2033.
tion,” said Kim Tait, senior curator of miner- scopic images of the samples, and other tests. “This is still very much a work in prog-
als at the Royal Ontario Museum in Toronto “Technology is evolving quickly, so the ress,” said Harrington. “We’re still making
and a member of both MSPG2 and its prede- instruments we propose today might be com- decisions and identifying benefits and draw-
cessor, MSPG1. “The material will be weighed, pletely different in 10 years anyway,” said backs of different implementation strategies.
photographed—we’ll have eyes on to deter- Tait. “What we really want to get down is the But we’re starting to narrow our focus. And I
mine what kinds of rocks they are. We’ll types of information that people will want to have no doubt we’ll be ready for it.”
already have some of that since the rover is extract from the samples.”
scrutinizing the rocks and gathering a lot of “The main purpose is to describe the sam-
field information.” ples to the extent needed so scientists know By Damond Benningfield, Science Writer
SCIENCE NEWS BY AGU // Eos.org 7
NEWS
Bright Lights, Big Cities Attract Migratory Birds
combined weather radar data from 2016 to
2020 across 143 locations with environmen-
tal models to catch birds on the wing after
sunset across the contiguous 48 states.
Weather radars, along with data from NASA
satellites like Landsat, register the massive
densities of thousands of birds taking off
during dusk and help predict regional hot
spots during the spring and fall migration
seasons.
The scope of this project, however, only
recently became feasible. “The technology
and advances that we’ve seen with satellite
and radar information in the last 20 years
“The technology and
advances that we’ve seen
with satellite and radar
information in the last
20 years have been such
L that we can now do
ike moths to a lamp, billions of birds Lands at Colorado State University who was
flock to brightly lighted urban areas— not involved in the study. The new project
far from the natural resources they need provides important information to help the these kinds of studies.”
on their journeys—as they migrate across preservation of natural areas key to the birds’
North America during spring and fall. Light safe passage.
pollution is attracting migratory birds.
“It almost acts as a beacon to them, and Mapping Birds on the Wing have been such that we can now do these
they gravitate toward it,” said Amy Collins, a Many natural habitats attract and support kinds of studies,” said Collins. “I would say
postdoctoral research fellow in fish, wildlife, migratory birds, including forest cover, corri- even 5 years ago we probably wouldn’t have
and conservation biology at Colorado State dors along rivers and streams, marshes, ponds, been able to do this.”
University. and stretches of vegetation lining bodies of Historically, ornithologists would complete
As these avian species fly over urban water. Birds gravitate toward forests or for- laborious in-person bird surveys in particu-
sprawl, they waste precious energy navigating ested habitats to rest in protected areas, while lar migratory locations—a constant logisti-
urban environments and are most affected riparian corridors provide water and food. cal challenge for access and staffing. Now the
during dusk and dawn, when most migratory radar and satellite data offer another way
birds usually take flight. to identify migration hot spots to study and
Although experts already knew that noise protect. “It’s a nice complement for all those
and light pollution can affect bird species, the A heavily lighted area other forms of data that we’ve been collecting
extent of the intrusion isn’t well defined. To for years and years,” Collins said.
provide more answers, Collins and colleagues “almost acts as a beacon to The new data helped show Collins and col-
created a new atlas of stopover locations and [migrating birds], and they leagues the birds’ hot spot stopovers. “We’re
migratory hot spots that was presented at seeing spring hot spots in California, Texas,
AGU’s Fall Meeting 2021 (bit.ly/stopover gravitate toward it.” a bit of the Midwest,” she said, “and then
-atlas). The new work shows the extent to in fall, real hot spots in the Midwest.” With
which cities affect the travel plans of birds— “aeroecology” becoming more critical as the
and the factors driving these stopover deci- threats to migratory birds increase, Collins
sions. In contrast, light pollution and tall build- noted, a combination of radar, satellite, and
“Urban life can be disorienting for migrat- ings artificially attract migrating flocks, chal- field research seems like a natural next step.
ing birds…and a lot of wildlife is struggling to lenging them with high levels of interaction
adapt to that setting,” said Danielle Ferraro, with humans, structures, and roadways.
a natural resources specialist for the Center To shed light on the problem, Collins and By Brian Phan (@PhantasticTides), Science
for Environmental Management of Military her colleagues at Colorado State University Writer
8 Eos // FEBRUARY 2022NEWS
Peruvian Farmers Threatened by Water Stress
A
griculture is an important part of city are more profitable but also prone to price lished in 1983. The project transfers water
life in Arequipa, Peru, a regional cap- crashes and sometimes are more dependent from the Colca River in the Andean Highlands
ital that has seen its population grow on irrigation. Currently, there is a drive to to the Atacama Desert below, creating a fer-
to nearly a million, from just 160,000 in 1960. grow avocados in Arequipa, for instance, tile area of roughly 23,000 hectares. In the
People are drawn to the city by financial and which require significant amounts of water to early days of the project, plots of land (5 hect-
social opportunities and because of internal cultivate. ares each) were sold inexpensively through a
conflict that particularly has affected Peru’s Tomasek is part of a research project, sup- lottery system.
rural communities. ported by the Arequipa Nexus Institute,
Water is supplied to urban farms via a pre- investigating water disparities in the Are-
Incan canal network, which distributes water quipa region. She is particularly concerned
from the Chili River. But as the city has about plans to build a new hydroelectric plant As farmers sell their land,
expanded into surrounding rural areas, many in the city’s northern outskirts that will flood
farmers are choosing to sell their land to historic farmland. As a result of the dam, “there is a real danger that
developers. water for Arequipa’s city farms would be Traditional Knowledge,
Researchers noted that as smallholder pumped rather than fed by gravity—leaving
farmers sell their land, traditional agricul- farmers more exposed to supply issues. such as crop rotation
tural knowledge may be lost, although the Environmentalists are also concerned and drought adaptation,
region’s growing population means that agri- about what effect continued expansion of the
culture itself is expanding into previously arid Cerro Verde open-pit copper mine, 32 kilo- will be lost and the city
regions. “There is a real danger that Tradi- meters southwest of Arequipa, might have on
will be less resilient.”
tional Knowledge, such as crop rotation and the region’s water supply. Mine officials said
drought adaptation, will be lost and the city that wastewater is treated to ensure that
will be less resilient,” said Abigail Tomasek, heavy metals (such as copper, arsenic, and
a geoengineer at Oregon State University in cadmium) don’t pollute local water networks.
Corvallis. Tomasek presented findings from Majes is officially home to more than
her research at AGU’s Fall Meeting 2021 in Flooding the Desert 60,000 people, although some estimates put
New Orleans (bit.ly/water-imbalance). Meanwhile, just 88 kilometers west of the city its population as high as 120,000. The year-
Historically, Arequipeños have grown a of Arequipa (but still in the Department of round water supply ensured by the Majes-
variety of crops, including potatoes, broccoli, Arequipa) is the Majes District, a newer set- Siguas project attracts migrant farmers and
and alfalfa. In recent years, market forces tlement facing its own water stress. Peruvi- farmworkers who previously had limited
have driven city farmers to focus on mono- ans began moving to this arid area after the growing seasons. Many of these farmers hail
culture crops such as onions and garlic, which Majes-Siguas irrigation project was estab- from Andean Highland communities that his-
torically relied on seasonal meltwaters from
glaciers, which are now retreating because of
climate change. Many landowners in the
region hail from Arequipa and hire farmwork-
ers from Peru’s highlands and other cities
such as Puno.
“Multiple factors drive people to live in a
place like Majes where there is work, where
there are better schools. Climate is definitely
a factor, but it’s not the only one,” said Anna
Erwin, a social scientist from Purdue Univer-
sity in Indiana who this year will begin a new
post at the University of Texas Rio Grande
Opposite: Salaam Halila, CC BY-SA 4.0 (bit.ly/ccbysa4-0)
Valley.
To prepare for dry periods, registered land-
owners store water in reservoirs and take
other measures agreed to through an irriga-
tion commission. Migrant farmworkers usu-
ally do not have a voice in these commissions;
legally, they cannot access water from the
irrigation project.
Erwin interviewed migrant farmworkers
and a range of other actors in Majes in 2019 as
Anna Erwin interviews a migrant farmworker at the Majes-Siguas irrigation project in Peru. Credit: Arequipa part of the same research project as Toma-
Nexus Institute sek’s. In December 2021, Erwin returned to
SCIENCE NEWS BY AGU // Eos.org 9NEWS
Majes for a follow-up study, funded by Pur-
due’s Clifford B. Kinley Trust, that also con-
Hostile Workplaces Drive Minorities
sidered the effects of the COVID-19 pandemic
on the migrant farming community. She dis-
from the Geosciences
cussed this work at AGU’s Fall Meeting 2021
R
(bit.ly/migrant-water). ecruitment efforts have helped even The findings come from the ADVANCEGeo
“When there is no water, the harvest dries out gender divides and increase the Partnership climate survey and represent one
out, everything [dries out], and there is noth- presence of people from minoritized outcome of a 4-year partnership between
ing to drink,” one migrant farmworker (who groups in Earth, space, and ecological sci- the Association for Women Geoscientists,
preferred to remain anonymous) told Erwin ences (ESE), but hostile workplace conditions Earth Science Women’s Network, and AGU to
and the persistence of discriminatory, sexist, address sexual harassment in ESE. The effort
ableist, and racist behaviors continue to dam- is funded by the National Science Founda-
age retention rates, a new survey has found. tion’s ADVANCE program and is tasked with
“I don’t think that many academics and developing bystander intervention work-
“When there is no water, scientific fields acknowledge that retention is shops for academia.
the harvest dries out, also an important factor in increasing diver-
sity in STEM,” said Emily Diaz-Vallejo, a doc- A Long-Standing Problem
everything [dries out], and toral student in geography at the University Diaz-Vallejo said that even within STEM, ESE
there is nothing to drink.” of Wisconsin–Madison and lead author of a fields have exceptionally low representation
poster on the findings, which she presented despite recruitment efforts. It’s a problem
during AGU’s Fall Meeting 2021 (bit.ly/hostile that’s hardly news to Ebony Omotola McGee,
-workplace). “If this is not fixed, then diver- a professor of diversity and STEM (science,
sity in the geosciences may still continue to technology, engineering, and mathematics)
during her research. If water cuts out for even be what it is.” education at Vanderbilt University and the
a couple of days, flowering crops like potatoes With 2,489 respondents from scientific author of Black, Brown, Bruised: How Racialized
and peppers can die, and pests can thrive. memberships and organizations, the survey STEM Education Stifles Innovation. She said that
In these circumstances, migrant farm- results showed that people in minoritized the size of the survey and its specificity to the
workers are often forced to buy water at exor- groups, including people of color, women, and geosciences might be new but that hostile
bitant prices. Some resort to stealing water people with disabilities, had more negative workplaces affecting diversity in STEM was a
from the irrigation system, which leads to experiences. They also reported an increased frustratingly familiar problem—and one that
landowners blaming migrants for reductions desire to leave the field, feeling unsafe, and has been centuries in the making. Addressing
in the water flow supplying their farms. experiencing low productivity at work as a it, McGee said, requires broader, systemic
result of these experiences. Respondents changes, like questioning the way STEM
Majes-Siguas II were split among early- career (20%) and departments are set up.
There are now plans for a public-private part- later-career (80%) professionals. “How is STEM functioning within that
nership to create an additional 38,500-hectare “There is this idea that if we get a lot of space? How was it created? Who are the cre-
irrigation zone dubbed Majes-Siguas II. Indi- these minority groups in the recruitment ators?” she asked. “What part of that creation
vidual plots will be significantly larger than in processes, then if they accept to be in the field story is foundational to even somebody who
Majes-Siguas I, so it will likely attract bigger or in the academy, then we will have more walks into our current geoscience class-
business. representation,” Diaz-Vallejo said. rooms? Who are the faculty? How were they
In an upcoming research paper, Erwin and Yet survey results showed that recruitment hired? Was there bias in their hiring?”
co-researchers describe how migrant com- alone isn’t enough. Still, why is the emphasis on recruitment,
munities currently self-organize to pool water Overall, 32% of nonbinary respondents and as Diaz-Vallejo describes, when hostile work-
resources and obtain electricity supplies. The 22% of women reported receiving disrespectful place environments are directly linked to attri-
team recommends that these farmers be and derogatory comments in ESE workplaces, tion? McGee said it comes down to systemic
included in existing water organizations to and survey data showed a negative correlation bias and widespread structural problems.
strengthen resilience. between these harmful remarks and respectful “The people who are built in [STEM] are
Jorge Delgado Ochoa, a psychologist and workplace environments. Intimidation was white, male, middle to upper middle class and
sustainable development consultant based in reported most often by people with disabili- have been socialized to think that they are
Cusco, said that baseline water use studies ties (12%), who were also the most likely to fear somehow neutral, universal, objective, and
(such as those from Tomasek and Erwin) can for their physical safety. People of color (7%) there’s nothing political about what they
inform interventions to support Peru’s rural were more likely than other groups to experi- do—it’s not racist,” McGee said. “And this
communities. “Peru is famous for its geo- ence sabotage or challenges to their expertise; ideology, the lack of interrogation of how race
graphical diversity and resources, so it is rel- these behaviors were associated with work- and racism may play a role or being minori-
evant to find a middle point to keep traditions places where workers felt that their opinions tized may play a role within that culture, is
but also keep mining operations and electric- were not considered or safe to share. On the just simply not done. It’s not done despite the
ity generation,” he said. whole, people who experienced bullying, sab- nice, glossy diversity statements.”
otage, challenges to expertise, or derogatory
remarks were 1.5–2.5 times more likely to con-
By James Dacey (@jamesdacey), Science Writer sider leaving ESE fields than their peers. By Robin Donovan (@RobinKD), Science Writer
10 Eos // FEBRUARY 2022NEWS
A Hotter Earth Means Stronger Tornadoes
Mateusz Taszarek, a researcher of severe
thunderstorms from Adam Mickiewicz Uni-
versity in Poland, said that pseudo– global
warming methodology complements two
approaches that researchers have previously
used to study how severe storms (which have
the potential to cause tornadoes) will change
under future climate conditions. He and other
researchers have examined changes in severe
storm frequency over the past few decades
and have also assessed the potential for
future atmospheric conditions to support
severe storms.
Results have recapitulated Woods’s find-
ings, but Taszarek thinks the locations Woods
examined are as important as the seasons.
To the left of a tornado that formed near Goodland, Kan., on 9 June is a funnel cloud, that also became a tor- Previous research predicted that tornado fre-
nado. Credit: Matthew Woods quency will decrease in the Great Plains but
increase along the Gulf Coast. Taszarek added
that strong winds brought on by the jet
stream are likely to further increase tornado
O
n 20 May 2013 at 2:56 p.m., a tornado mate models are intended to describe wide- frequency along the Gulf Coast during the
touched down in central Oklahoma. spread effects, and most consider only points winter months, the season when the outbreak
Over the next 40 minutes, it ripped spaced tens or hundreds of kilometers apart, Woods modeled occurred.
through the towns of Newcastle, Moore, and whereas most tornadoes are around 50–100 Meteorologist Pieter Groenemeijer from
south Oklahoma City. The storm destroyed meters across. “Climate models, they don’t the European Severe Storms Laboratory
dozens of houses and cars, two farms, two explicitly resolve or capture storms because agreed that Woods’s approach is a valuable
elementary schools, a strip mall, and several the storms fall between the grid points,” complement to previous work, but he and
other buildings as it killed 24 people and Woods said. Taszarek stressed the need to examine more
injured hundreds. Instead, Woods turned to pseudo–global events. “I think this is actually probably the
Climate change is known to affect many warming methodology, in which researchers thing that is most important—that they
types of extreme weather, such as hurricanes, model historical weather events over small would simulate more of these historical out-
droughts, and floods. But until recently, few geographic areas using conditions that breaks and see if they get a consistent sig-
studies had addressed whether it will affect mimic what future weather conditions could nal,” Groenemeijer said.
tornado outbreaks like the one that deci- look like. Woods modeled two historical
mated central Oklahoma. Matthew Woods, a events: the 20 May 2013 Oklahoma tornado Protecting Vulnerable Populations
recent graduate of the University of Illinois at outbreak and a 10 February 2013 outbreak Taszarek is particularly interested in Woods’s
Urbana-Champaign, aimed to fill that gap that took place along the U.S. Gulf Coast. model of the Gulf Coast tornado outbreak
with his recent research in atmospheric sci- Both events involved extremely strong tor- because it took place in a highly populated
ences and meteorology. nadoes capable of inflicting severe damage. region with variable landscapes where it’s
“Climate change certainly raises the ceiling Woods adjusted conditions such as tem- difficult to see storms approaching. In addi-
for future tornadoes, in terms of strength,” perature, humidity, wind, and soil moisture tion to performing more studies like Woods’s,
Woods said. Using a modeling framework that to account for changes that are predicted to he thinks scientists need to research commu-
the researchers called pseudo–global warm- occur by the 2090s according to five differ- nication strategies that will help the public
ing methodology, he predicted that the fre- ent climate models, then simulated what appreciate the risks posed by storms. “I think
quency of warm- season tornadoes will the Oklahoma and Gulf Coast tornado out- there’s a lot of social science that needs to be
decrease slightly in the United States, but breaks would look like in each scenario. done,” he said.
those that do occur may be stronger. Mean- Simulating the spring Oklahoma outbreak Woods also worries about the potential for
while, the cool season is likely to see both suggested that tornado occurrence will future storms to affect population centers.
more frequent and more intense tornadoes. decrease by about 15% during the warm sea- “The risk in the future is going to likely
Woods shared his results at AGU’s Fall Meet- son, but tornadoes that do occur are likely to increase, not only because of climate change,
ing 2021 during a poster session (bit.ly/ be nearly 100% stronger. Meanwhile, mod- but just because of population growth,” he
tornado-intensity). eling the winter Gulf Coast outbreak told said. “We’re making the target bigger.”
him that the probability of tornado occur-
Studying the Past to Predict the Future rence in the cool season will increase by
Tornadoes are very localized, which makes around 400%, with substantial increases in By Saima Sidik (@saimamaysidik), Science
them difficult for climatologists to study. Cli- storm intensity. Writer
SCIENCE NEWS BY AGU // Eos.org 11NEWS
Earthquakes Ripple Through 3D-Printed Models
of Los Angeles
S
ome of the world’s largest cities— commonly used to study the Los Angeles 1:250,000. “It has all these structures within
including Los Angeles, Mexico City, basin, said Park. it,” said Park.
and Santiago—are located in naturally After experimenting with such materials
occurring sedimentary basins. Add in the fact as rubber and plastic, Park and her colleagues Earthquakes from Lasers
that these cities are prone to earthquakes, settled on stainless steel as their preferred The team members generated extremely tiny
and that’s potentially a recipe for disaster: printing medium. That choice was mainly earthquakes in their models by bombarding
Numerical modeling has suggested that dictated by steel’s rigidity, said Park. “If it’s them with megahertz-frequency laser light.
ground shaking is amplified within basins. rigid, it has a much larger range of material The thermal energy of the laser pulses heated
But such modeling—an oft-used resource properties.” the models, resulting in differential stresses
for understanding ground motion in sedi- The researchers printed their models much that translated into movement, albeit very
mentary basins—is often limited in its spa- in the same way that ink is printed on paper: small: Park and her colleagues recorded
tial resolution and is furthermore con- They laid down successive layers of powdered ground motion at the top of the models on the
strained by the equations it receives as input. stainless steel and then used a laser to heat order of tenths of nanometers.
Now, to more thoroughly study how seismic and join (sinter) the layers together. By
waves travel through a sedimentary basin, changing the printing parameters—includ-
researchers have conducted a series of seis- ing the speed of the sintering laser and its
mic experiments using 3D-printed models of power—it’s possible to control how much
the underbelly of Los Angeles. They found pore space remains, said Park. “That’s how “We don’t want to have
that the highest-frequency seismic waves— you can print a variable range of densities.” our model running
those that generate sudden changes in accel- The models the researchers produced,
eration and are therefore the most destruc- measuring roughly 20 × 4 × 1 centimeters for 20 years.”
tive to buildings—were actually attenuated thick, aren’t much to look at from the outside,
within the models’ basin. That’s wholly said Park. But each one captures a range of
unpredicted by numerical models, the team geological structures within the 50-kilometer
noted. -wide Los Angeles basin at a scale of
The researchers found that higher fre-
Trade-Offs to Consider quencies of ground motion in their models—
Sedimentary basins are complex geological corresponding to real-life frequencies above
structures. They start out as depressions that 1 hertz—were generally reduced within
over time become filled with lower-density basins. Those waves tended to be selectively
material deposited by rivers and landslides. reflected back at the edges of a basin, the
“Imagine a bowl being filled up with stuff,” team showed.
said Chukwuebuka C. Nweke, a civil engineer That’s a surprise, said Park, because sedi-
who works on natural hazards at the Univer- mentary basins have long been believed to be
sity of Southern California in Los Angeles who amplifiers of ground motion. “[These results]
was not involved in the research. are in some sense opposite of our conven-
But reproducing the small-scale details of tional understanding.”
a sedimentary basin in a numerical model is These results were presented at AGU’s Fall
challenging, said Nweke, given inherent Meeting 2021 (bit.ly/3D-LA-models).
trade-offs between a model’s spatial resolu- There’s plenty more to investigate using
tion and the computational time required to these models, the researchers suggested. One
run it. “We don’t want to have our model run- unexpected finding from the scientists’
ning for 20 years.” experiments was that their laser pulses trig-
gered not only seismic waves but also air-
A Boost in Resolution borne waves that skimmed over the models’
For that reason, Sunyoung “Sunny” Park, a top surfaces. Because such waves are strongly
seismologist at the University of Chicago, and affected by local topography, logical follow-
her colleagues recently began 3D printing on work could include adding features like
models of the Los Angeles basin. Park and her hills and mountains to the models’ surfaces
team realized that they could reproduce even and then measuring how the airborne waves
relatively small natural variations in den- propagate, Park said.
sity—corresponding to about 10 meters in
size in real life—in their 3D-printed models. To better understand earthquake hazards in the
That’s roughly a factor of 10 better than the Los Angeles basin, researchers are turning to By Katherine Kornei (@KatherineKornei),
spatial resolution of a numerical model that’s 3D-printed models. Credit: iStock.com/eyfoto Science Writer
12 Eos // FEBRUARY 2022NEWS
Asteroid May Be a Chip off the Old Moon
N
ear-Earth objects are fragments of
rock that orbit the Sun along paths
that remain close to Earth. Research-
ers study these objects to assess their threat
level and also to improve our understanding
of the solar system. Most of these objects
are difficult to measure, but one asteroid,
Kamo‘oalewa, maintains a stable orbit and
makes a regular pass of Earth every April,
opening a window to study this chunk of rock
in greater detail.
A team of researchers at the University of
Arizona has evaluated spectral data collected
over several years and determined that
Kamo‘oalewa may actually be a fragment of
the Moon. The results of the study were pub-
lished in Nature Communications Earth and
Environment (bit.ly/lunar-silicate). Near-Earth asteroid Kamo‘oalewa, shown here in an artists illustration, might be a lost fragment of the Moon.
“What was supposed to be a quick one- Credit: Addy Graham/University of Arizona
and-done summer project turned out to be
way more interesting,” said Benjamin Shar-
key, a graduate student in the Lunar and
Planetary Laboratory at the University of Ari- limited time, astronomers can make obser- of those options provided an adequate expla-
zona and lead author on the paper. “As we vations on the faint cosmic phantom. nation for Kamo‘oalewa’s spectral data. A
keep pushing discoveries to fainter things in Sharkey and his team gathered data about lunar match made the most sense.
different parts of the sky, it is exciting to open Kamo‘oalewa using two powerful telescopes
new populations [of objects] to characterize,” in Arizona, the Large Binocular Telescope on Maybe a Missing Link
he said. Such analysis allows scientists “to Mount Graham and the Lowell Discovery “The general understanding is that near-
rewind time to explain how the solar system Telescope in Flagstaff. They measured the Earth objects evolved from collisions in the
formed and evolved.” asteroid’s spectrum of electromagnetic radi- main asteroid belt, and then through gravi-
ation to determine its composition. tational resonances their orbits evolved to be
“We do geology by looking out with tele- near the Earth,” said Paul Chodas, manager
scopes rather than [by] looking down,” of the Center for Near-Earth Object Studies
explained Vishnu Reddy, an associate profes- at the Jet Propulsion Laboratory in California.
“This would be the first sor at the Lunar and Planetary Laboratory and Chodas did not participate in this study. “This
time we have evidence that a contributing author on the paper. would be the first time we have evidence that
The team compared Kamo‘oalewa’s spec- an asteroid originated in the Earth-Moon
an asteroid originated in tral data to stony and chondrite-rich aster- system.”
the Earth-Moon system.” oids and meteorites, as well as to lunar rocks Reddy, Sharkey, and their colleagues
collected during the Apollo 14 mission. wanted to gather more data to confirm these
Kamo‘oalewa’s reflectance spectrum is red- startling results, but they had to wait 2 years,
der (indicating higher reflectance at increas- having lost their opportunity in 2020 because
ing wavelength) than either the asteroids or of the pandemic.
Analyzing an Oscillating Fragment the meteorites, but when Sharkey compared Sharkey collected new data in 2021 and
The fragment was discovered in 2016 by Pan- It’s data to an Apollo 14 lunar rock, they were they supported the original analysis:
STARRS (Panoramic Survey Telescope and a match. Kamo‘oalewa most likely originated on the
Rapid Response System) facilities at Haleak- “When I first looked at the data, I thought, Moon. How and when it broke free from the
ala Observatory in Hawaii. Kamo‘oalewa’s this is too good to be true,” said Reddy. lunar surface remain a mystery.
name is derived from Hawaiian and means But was it? “This could be the missing link between
“the oscillating fragment.” It is relatively Reddy encouraged Sharkey to explore every the craters on the Moon and lunar meteorites
large for a near-Earth object, measuring option to explain the spectral data. Reddening, on Earth,” said Reddy. “We need to conduct
about 46 meters in diameter, and has fol- for instance, can be influenced by the angle follow-up studies to explore other objects in
lowed an orbit similar to Earth’s for several between a celestial object and the observing the solar system, but it is exciting to see what
centuries. At its closest pass, Kamo‘oalewa telescope. Particle size on the object’s surface, is to come.”
travels within 14.5 million kilometers of the metal content of surface rocks, and the
Earth, more than 37 times the distance level of space weathering can also contribute
between Earth and the Moon. During this to reddening. Sharkey investigated, and none By Stacy Kish (@StacyWKish), Science Writer
SCIENCE NEWS BY AGU // Eos.org 13NEWS
A New Technique Could Identify Algae from Space
A
lgae form the basis for many aquatic Surveillance of Harmful Algal Blooms
food webs, but when certain algae, (SMASH) that they hope will one day allow us
bacteria, or other tiny photosyn- to determine the type of microbe in a bloom
thetic organisms start to grow out of con- from satellite images. The scientists pre-
trol—a phenomenon called an algal bloom— sented their research at AGU’s Fall Meeting
they can cause major problems. Harmful algal 2021 (bit.ly/habs-inland).
blooms (HABs) disrupt ecosystems, nega- For now, said Carl Legleiter, a hydrologist
tively affect drinking water supplies, and at the USGS Geomorphology and Sediment
threaten human health worldwide, costing an Transport Laboratory and one of the scien-
estimated $4 billion per year in the United tists working on the SMASH technique, the
States alone, said Tyler King, a hydrologist at research is still in the proof- of- concept
the U.S. Geological Survey’s (USGS) Idaho stage. Currently, he said, researchers are
Water Science Center. working on creating a spectral library—a set
Because of the sheer scale of the problem, of reflectance characteristics for various
HABs are difficult to monitor from the microbes, measured using a microscope and
ground, so scientists are working on ways to a hyperspectral camera. Using this library,
monitor them more effectively from space. along with the reflectance of the water in a
Currently, scientists, including those at the lake, they try to identify the best match for an
U.S. interagency Cyanobacteria Assessment algal bloom in a satellite image. Early suc-
Network (CyAN) project, are working on cesses included identifying blooms of the
using satellite images to identify and monitor freshwater cyanobacteria Microcystis and Aph-
the spread of algal blooms that involve cya- anizomenon (both of which can produce toxins
nobacteria, which can be particularly prob- damaging to human health) in lakes in New
lematic. York and Oregon, respectively.
Other specialists in remote sensing of algal
blooms are also enthusiastic about the tech-
nique. “It would be great if you could get more
The problem of algal specific about what type of plankton is in the Algal blooms, like the one pictured here in Lake Erie,
system,” said Bridget Seegers, the NASA lead threaten ecosystems and human health. Credit:
blooms “is going to only scientist on the CyAN project, who was not European Space Agency, CC BY-SA 2.0 (bit.ly/
increase in significance in involved in developing SMASH. ccbysa2-0)
the future, because one of Preparing for the Future
the risk factors is elevated Right now, most satellites aren’t capable of
gathering the hyperspectral images needed ment practices, those kinds of things, can
water temperatures.” for this kind of analysis. SMASH uses data also be contributors.”
collected by a device on the International Indeed, a 2019 study showed that globally,
Space Station, which means that the coverage freshwater blooms have generally become
is limited, said Legleiter. But it won’t be this more intense over the past few decades (bit
way forever. “There are multiple hyperspec- .ly/lake-blooms). Seegers said that currently,
But there are many, many types of microbes tral satellites slated for launch in the coming efforts are focused on improving our ability
associated with HABs—even the term cyano- years,” he said. to monitor these blooms in near-real time.
bacteria encompasses thousands of species— Techniques like SMASH, said Seegers, “are However, tracking the prevalence of blooms
and available technology isn’t very good at good prep for the kind of satellites that are in a specific location over time might enable
telling them apart using satellite data. This is coming.” researchers to identify local changes (like dif-
important, because although many species In the meantime, researchers will be busy ferences in land use or agricultural practices)
are relatively benign (at least in terms of dan- adding more species to the spectral library associated with increased blooms, which
ger to human health), blooms of certain spe- and trying out SMASH in more lakes across could help identify ways to prevent them in
cies produce potent toxins that affect the ner- the United States. the future. The more we understand about
vous system or liver. Determining whether a The problem of algal blooms, said Leg- harmful algal blooms—which species are
bloom is made up of these dangerous species leiter, “is going to only increase in signifi- involved, the conditions that precipitate
is a key part of creating an effective manage- cance in the future, because one of the risk them—the better we’ll be able to address this
ment plan to protect people from the negative factors is elevated water temperatures. You global problem.
effects of the bloom. may have heard—things are warming up on
Scientists at USGS, including King, are hard this planet. And another potential driver is
at work on this problem, developing a tech- nutrient enrichment from agricultural runoff. By Hannah Thomasy (@HannahThomasy),
nique called Spectral Mixture Analysis for So changes in land use and poor soil manage- Science Writer
14 Eos // FEBRUARY 2022You can also read
